Within industries that use lined pipes, among which is the mining industry, steel pipe is manufactured and may be installed for multiple purposes. Steel pipe can be connected or joined in a variety of ways depending on the application and design requirements. One of the struggles that currently exists with pipes having internal cement or rubber linings is obtaining quality welds when connecting two pieces of beveled end steel cement-lined or rubber-lined pipe. Currently when two sections of pipe are joined together, beveled end against beveled end, and the initial weld pass (referred to as the “root pass”) directly contacts the cement or rubber lining, resulting in both contamination of the welding and weakening of the cement or rubber during the root pass. The result is that the completed weld joint strength is reduced due to this contamination. Also this joint type does not allow a quality mechanical or nondestructive test of the completed welded joint.
In order to overcome this problem with concrete contamination, the thickness of the pipe wall has been increased by about 20% or greater than necessary for most applications. Such a solution results in about a 20% or greater increase in the cost of materials. A more cost effective solution to preventing concrete contamination when joining lined pipes by welding is therefore desired.